Bobbin for electrical weft detectors



R G. TURNER 1,832,595

BOBBIN FOR ELECTRICAL WEFT DETECTORS Filed June 14, 1929 Nov. 17, 1931.

IZ-Q7 @MHA/CPD ./5. TURN/5H A TTU/maf Patented Nov. 17, 1931 UNITED PATENT OFFICE RICHARD G. TURNER, 0F WORCESTER, MASSACHUSETTS, ASSIGNOR- TO CR-OMPTON KNOWLES LOOM WORKS, WORCESTER, MASSACHUSETTS, A CORPORATION 0F MAssAoHUsE'rTs BOBBIN non ELECTRICAL WEET Dn'rncfrons Application filed .Tune 14,

This invention relates to improvements in bobbins to cooperate with electrical weft detectors f or looms it is the general object of the invention to provide an improved form of metallic area or surface for the bobbin.

It is customary to use weft detectors with bobbins having zones or surfaces made of electric current conducting material, such as are presented by metallic ferrules, and to employ two contact ele-ments which when electrically connected by the metallic surface will complete a circuit effective to produce a change in the operation of the loom. It is a further objectof my present invention to provide a hollow paper bobbin with a winding of wire which will in eli'ect present a substantially continuous metallic surface to cooperate with the electrical contact elements.

It is a further object of my invention to apply to a weft carrier having circular grooves a wire the ends of which project through the walls of the carrier into the 1nterior thereof to be bent so as to hold the wire in proper position to prevent unwinding of the several coils, the ends of the wires preferably extending through the grooves so that no part of the wire adjacent the end of the zone will project into the path of weft as the latter is unwound.

With these and other objects in view which will appear as the description proceeds my invention resides in the combination and arrangement of parts hereinafter described and set forth in the claims.

In the accompanying drawings wherein a convenient embodiment of my invention is set forth,

Fig. l is a top plan view of the preferred form of weft bobbin made according to my `present invention, having a mass of yarn wound thereon and located in a shuttle preparatory of being presented to the elements 192'9. Serial No. 371,006.

ing the manner of attaching the ends of the wire to the bobbin, Y

Fig. 'is avertioal section on line 5 5 of Fig. 4,

Fig. 6 is a view similar to Fig. 2 showing a modification, and ,Y

7 shows the modified form of coiled spring in norm al condition.

Referring to Fig. 1, I have shown a shuttle S having a spindle P which supports the wound mass of weft W. The latter is wound on a paper tube indicated at 10 and has in the body thereof circular grooves 11 which serve to hold lthe yarn in position on the bobbin. rEhe tube is tted over the spindle `P and is held frictionally thereto during the operation of the shuttle. e

A slot 12 is formed on the forward wall 13 of the shuttle to provide entry for a pair of electrical contacts 14 andv15 which may be connected, respectively, to the positive and negative side of an electric circuit not shown. It is to be understood that these contacts are part of a normally open circuit including mechanism effective when energized by electric current to bring about a change in the operation of the loom,such, for instance, as stopping the loom or causing weft replenishment. It is suflicient for the purposes of my present invention to state that when the bobbin to be set forth more particularly hereinafter electrically connects the contacts 14 and l5 due to substantial exhaustion of weft, a change will occur in the operation of the loom.

In carrying the preferred form of my invention into effect I provide a metallic wire 2O land extend one end 2l thereof through a wall of the tube 10 and bend said vendto one side, such, for instance, as longitudinally of the bobbin as indicated at 22 in Fig. 4. With the end thus held I wind the wire helically along the exterior surface of the tube for a distance somewhat in excess of the distance between the electric contacts 14 and 15. The coils or convolutions are wound closely together as suggested in F ig. 2 and when a suficient length of 4them has I been provided Il extend theother end 23 through the tub'e,'preferably through the bottom of one 'los of the grooves 11 and bend said end to one side, as at 24. This second end may be drawn tightly by means of a properly formed tool inserted into the larger end of the tube. The several coils are all in electrical contact with each other and present a. substantially continuous metallic surface.

As the yarn is Withdrawn from the tube during weaving the coils of the Wire Q0 will eventually be exposed to effect electrical contact between the elements 14 and 15, whereupon the previously7 mentioned change in the operation of the loom will take place. It is to be understood that because of the manner of making the Zone of electric conducting surface it is permissible to make the latter of any desired length and that the winding of the weft over said coils tends to keep them in proper position so that they Will not be disturbed by the movements of the shuttle during the weaving operation.

In the modified form the coiled spring is wound to have an internal diameter less than the outside diameter of that part of the bobbin to which it is applied. As shown in Fig. 6 the bobbin has a conical portion 30 which lies opposite the contact elements 14 and 15. The coil 31 normally has coils of uniform diameter, as shown in Fig. 7, and is forced over the conical part 30. In this operation the coils are expanded and therefore grip the bobbin firmly to resist longitudinal movement relatively to the bobbin during Weaving. The spring 31 acts as does the coil in the preferred form to establish contact between the elements 14 and 15 at weft depletion. In order to protect the yarn I terminate one end at least of the coil 31 in a` groove 11. as in the preferred form.

From the foregoing it will be seen that I have provided a. very simple bobbin wherein a zone of electric conducting surface is provided by a wire coiled over a. portion of the length of the tube or bobbin. It will also be seen that in both forms at least one end of the coiled wire may terminate in a groove 11 to protect the weft. It will be seen in the preferred form that the ends of the wire extend into the tube and are bent laterally so as to hold the coils in proper position. In the modified form it will be noted that the strain set up in the coils of spring 31 tends to hold the latter in position on the bobbin. The stretching of the coils is due to the fact that they are normally of uniform diameter but are forced over a conical surface of larger diameter than the internal normal diameter of the coils. Furthermore7 in both forms the groove into which the wire extends serves to hold the coil in place.

Having thus described my invention it will be seen that changes and modifications may be made therein by those skilled in the art without departing from the spirit and scope of the invention and I do not Wish to be limited to the details herein disclosed, but what I claim is:

1. A bobbin having a body on which yarn is Wound7 said body having thereon a closely wound coiled spring presenting continuous electric current conducting surface, the normal internal diameter of the coils being less than the diameter of that part of the bobbin body which the coils engage.

2. A bobbin having a conical body to have yarn Wound thereon, said body having thereon a coiled spring presenting continuous electric current conducting surface, the coils of the spring being normally of uniform diameter but stretched over a conical part of the bobbin which is of greater external diameter than the internal diameter of the coils, whereby the coils are placed under a strain which tends to hold the spring in close engagement with and in proper position on the bobbin.

In testimony whereof I have hereunto affixed my signature.

RICHARD G. TURNER. 

